Pesticides to be used against pests are usually desired to be chemicals which exhibit sufficient controlling effects against a wide range of pests at low doses and further are capable of maintaining such effects for a certain period of time, when applied to pests, useful plants or useful crop plants, or to soil for vegetation of useful plants or useful crop plants or in the vicinity thereof. Especially, in recent years, from the environmental problems, it has been desired to develop a pesticide which is safer and has excellent pesticidal activities at a low dose.
On the other hand, Patent Document 1, discloses 1-[2-fluoro-4-methyl-5-(2,2,2-trifluoroethylsulfinyl)phenyl]-5-amino-3-(trifluoromethyl)-1H-1,2,4-triazole, and it is disclosed that such a compound is useful as a pesticide. The compound has an asymmetric sulfur atom, and therefore, presence of optical isomers is expected, however, Patent Document 1, discloses nothing about optical isomers.